<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      div {
        width: 600px;
        height: 600px;
        background-color: pink;
        display: flex;
        /* flex-direction: row;
        flex-wrap: wrap; */
        /* 简写 */
        flex-flow: row wrap;
      }
      div span {
        width: 180px;
        height: 150px;
        background-color: purple;
        color: #fff;
        margin: 10px;
      }
    </style>
  </head>
  <body>
    <div>
      <span>1</span><span>2</span><span>3</span><span>4</span><span>5</span>
    </div>
  </body>
</html>
